EGCG-Fe(II)配合物还原去除地下水源中Se(IV)和三氯乙烯的作用机制研究

针对目前我国多地区地下水受Se(IV)和三氯乙烯污染的问题，本项目拟在常规的亚铁还原体系中引入茶多酚EGCG，通过EGCG与亚铁的配位获得还原性能极强的环境友好的EGCG-Fe(II)配合物，从而实现对Se(IV)和三氯乙烯的还原去除。研究该配合物对水中Se(IV)、三氯乙烯的还原去除效能和影响因素，探讨其相应的动力学原理和反应机理。EGCG-Fe(II)配合物的形成改变了Fe(III)/Fe(II)电对的氧化还原电势，使Fe(II)得还原能力增强；另外，EGCG本身的还原性可以加速Fe(III)/Fe(II)的循环，使溶液中能始终保持较高浓度的还原剂，即Fe(II)配合物。从理论上分析，该方法相对于现有的化学还原技术，具有高效且无二次污染的特点。本项目研究成果为具有高还原性、环境友好型还原剂的研发与实际应用奠定理论基础，同时对于保障生态环境质量和饮用水安全具有重要的社会经济效益。

Addressed the issue that groundwater is polluted by Se(IV) and TCE in many areas in our country, EGCG, a kind of polyphenols extracted from tea, is introduced into the conventional Fe(II)-based reduction system to enhance reduction of Se(IV) and TCE. An environmentally friendly complex (EGCG-Fe(II)) with high reductive ability is resulted from the complex of EGCG and Fe(II). The performances as well as influence factors on reduction of Se(IV) and TCE by EGCG-Fe(II) will be investigated. Also, the kinetics and mechanisms of the reaction system will be evaluated. The formation of EGCG-Fe(II) changes the redox potential of Fe(III)/Fe(II) couple, which increases the reductive ability of Fe(II) species. Besides, the reductive ability of EGCG itself can accelerate the cycle of Fe(III)/Fe(II), maintaining a relatively high concentration of Fe(II) species in the solution. Theoretically, the proposed method is highly efficient and environmentally friendly potential compared to common chemical reduction technologies. The results of this study could lay the foundation for the development and application of other green reductive reagents. Meanwhile, the study is important from both social and economic aspects for ensuring quality of eco-environment and safety of drinking water.